The broad objective of the proposed research is to investigate and understand transducer mechanisms in the cochlea. At the present time the only vertebrate inner ear in which transduction at the cellular level has been investigated by recording the intracellular response in single hair (receptor) cells and the activity from single cochlear nerve neurons is the inner ear of the alligator lizard. This knowledge should lead to an understanding of the normal function of auditory receptor organ and to greater insights into the causes of deafness due to diseases of this organ. In order to relate the responses of single hair cells to the response of single auditory neurons it is essential to know how the neurons are connected to hair cells. It is the specific objective of this project to determine the pattern of innervation of the inner ear of the alligator lizard by the application of standard neuroanatomical techniques. BIBLIOGRAPHIC REFERENCES: Weiss, T. F., Mulroy, M. J., Turner, R. G. and Pike, C. L. Tuning of single fibers in the cochlear nerve of the alligator lizard: relation to receptor morphology. Brain Res. 115, 71-90, 1976. Nadol, J. B., Mulroy, M. J., Goodenough, D. A. and Weiss, T. F. Tight and gap junctions in a vertebrate inner ear. Am. J. Anat. 147, 281-302, 1976.